This invention relates to knitted tubular fabrics of single jersey construction producible on circular knitting machines of sinker-top design and to methods for producing said knitted fabrics to incorporate upstanding terry loops at certain portions on the technical reverse side thereof in complementary association with other flat-knitted stitch effects appearing at certain other portions on the technical reverse side and/or on the technical face of the fabric. The terry loop portions and the complementary flat-knit stitch portions together may constitute the full circumference of the knitted tubular fabric if desired.
The circular knitting machines to produce the fabrics of the present invention include continuously rotating pattern wheel means for selective actuation of elongated loop forming sinker elements in synchronized and complementary relationship with continuously rotating pattern wheel means for selective actuation of ground stitch forming latch needle elements. As used herein the term "complementary relationship" means that where one selected pattern area, i.e., an area in which upstanding terry loops are formed ends, the other area, a non-terry area, automatically picks up. The resulting fabrics may include, for example, on the technical reverse sides thereof, certain areas in which upstanding terry loops may be made to appear complemented by other non-terry areas in which flat-knitted surface interest effects may be incorporated.
It is well known in the knitting art to form elongated sinker loops (i.e. terry loops) on the technical reverse side of a fabric by introducing at a yarn feeding station two yarns in a plated relationship, one yarn constituting the ground yarn, and the other, the loop or terry yarn. With this well-known technology, a ground yarn is first introduced into the throats of the sinkers; after the sinkers have been advanced by appropriate cam means, the second yarn, i.e. the loop or terry yarn, is introduced into the hooks of the needles from a position above the nibs of the sinkers. Consequently, when the needles are subsequently fully retracted by stitch cam means, common stitches of ground and loop yarn are knitted together forming the basic fabric web, whereas the loop of terry yarn introduced over the sinker nibs is formed into elongated upstanding sinker loops appearing on the technical backside of the fabric.
The knitting sequence described in U.S. Pat. No. 3,477,255, FIGS. 1a through 2e, illustrates this well-known technique. It is also well known, as specifically shown in FIG. 2a of said U.S. Pat. No. 3,477,255, to advance selectively only certain sinkers to receive yarn over their nibs so that the elongated sinker or terry loops may be made to appear in patterned areas on the technical backside of the fabric and not elsewhere. The terry loop pattern areas may be regularly or randomly placed in symmetrical or asymmetrical arrangements, or combinations thereof.
It is also very old and well-known in the art to provide pattern wheel means for selective advancement of knitting elements, such as needles, to different yarn receiving levels whereby patterned effects in a ground fabric of single jersey are readily produced. These may be made to appear on either the technical face and/or the technical reverse side of the fabric. Such patterning means are described in U.S. Pat. No. 2,127,224.
It is also known in the art, as described in U.S. Pat. No. 2,116,358 to provide in a circular knitting machine needle selection drums and sinker selection drums intermittently and rotatably driven by means common to both. In this patent, the intermittently rotatable patterning drums for both needle and sinker selection comprise vertically positioned pattern drum means whose centerlines of rotation are vertical and thus parallel to the centerline of the circular knitting machine. Furthermore, the said intermittently rotatable pattern drum selection means interface with the sinker and needle knitting instruments through a multiplicity of intermediate cam elements, so that the said pattern drum selection means do not directly engage the knitting elements. Furthermore, during certain phases in the machine's operation, the pattern drum means for both the needle and sinker selection must be racked by conventional means well known in the art so that different pattern readings will be presented to their respective elements. These racking movements are synchronized at corresponding cylinder and dial locations.
In order to permit unencumbered racking movements of pattern drum means at the said cylinder and sinker dial locations, a narrow band of knitting elements, which normally would occupy these locations, is removed from the cylinder and sinker dial respectively.
Consequently, across the circumferential extent, no patterning is possible, and therefore, the tubular fabric produced is characterized by an unusable band in the fabric extending across the entire needle/sinker "out" area and running throughout the entire length of the fabric. Therefore, there is no possibility of using such fabric in tubular seamless body size applications.
In the subsequent finishing process, the tubular fabric is slit in the machine direction along this so-called needle/sinker "out" area. This restriction limits the knitgoods manufacturer who must slit the tubular fabric along the specific needle/sinker "out" portion rather than along some other position where, for example, defects in the fabric may exist.
On the other hand, pattern wheel selection as practiced in this invention is continuous, therefore not necessitating the removal of needles and sinkers from the cylinder and sinker dial members respectively. Consequently, continuous and uninterrupted patterning is readily achieved throughout the entire knitted tube of fabric. The fabric may, therefore, be slit along any wale location depending on the preferences of the manufacturer.
Furthermore, and importantly, since patterning with pattern wheel means is continuous throughout the circumference of the knitted tubular construction, pattern wheel selection as used in the present invention is uniquely suited to small diameter body size knitting wherein the fabric is finished in tubular form and subsequently cut and sewn tubularly for seamless body garment applications.
The fabrics of the present invention are producible by incorporating horizontally mounted pattern wheel means for sinker selection in combination with angularly mounted pattern wheel means for needle selection. The said pattern wheel means are continuously rotatable and derive their rotation by a direct meshing action with cooperating sinker and needle elements thus eliminating the requirement for intermediate camming. Further the sinker and needle pattern wheels are preferably provided with the same number of cuts so that the resulting pattern areas may be equal in width and depth.
The fact that the sinker and needle pattern wheels have an equal number of cuts will facilitate pattern preparation in that the sinker pattern wheel set-out and the needle pattern wheel set-out may be more simply and more expeditiously complemented with respect to each other so that where, for example, terry selection by sinker pattern wheel means stops, stitch selection by needle pattern wheel picks up, and vice versa. It will, however, be understood that although sinker pattern wheels and needle pattern wheels may preferably be of the same number of cuts, other combinations of cuts between the respective pattern wheels may likewise be advantageously employed to meet specific patterning requirements.
The method of the present invention resides in synchronizing the operations of these separate, independently operating distinct, pattern wheel means in novel cooperation whereby the terry patterning developed by the sinker pattern wheels is coordinated and complemented with the ground stitch patterning developed by the pattern wheels operating on the needles.
In other words, the sinkers are selectively advanced by continuously rotatable pattern wheel means at those positions in the fabric where terry loops are to appear. Simultaneously with this sinker selection, needles are directly selected to a full knit height in the same positions where terry loops are to appear. Furthermore, when sinkers are to remain retracted in their unselected positions in the so-called non-terry portions of the fabric, needle selection may be advantageously utilized to create unique ground stitch design effects comprising knit/tuck welt combinations and variations thereof. Consequently, selected needles cooperate with selected sinkers to form terry loops at first portions of the fabric; and furthermore, selected needles cooperate with sinkers selectively positioned to inoperative positions in other than an overall knit technique to form ground stitch effects at second portions of the fabric where terry loops do not appear. The first and second portions may easily be made within the same pattern areas, whereas those of the aforementioned U.S. Pat. No. 2,116,358 may not. By utilizing these two separate, distinct, and independently operating patterning systems in a novel and complementary manner, a broad range of surface, functional, and aesthetic effects are readily producible, thus enhancing patterning capabilities and market acceptance.
As noted earlier, a terry fabric produced on a circular knitting machine of sinker-top construction is, generally, referred to as single jersey in that knitted stitches are formed on a single set of needles and are pulled through to the technical face of the fabric. Fabric of this construction is characterized by a technical faceside in which knitted loops are readily discernible as vertical wales, and a technical backside, generally acknowledged to be flat, dull, and essentially nondescript. When upstanding terry loops appear on an overall basis on the technical backside of a single jersey fabric, they effectively conceal this essentially uninteresting base structure. However, in those instances where patterned or isolated terry effects are desired, the technical backside of the fabric is dull, flat and uninteresting at those areas where elongated terry loops are not formed. For example, if the terry loops are patterned in, say, a polka dot motif with the polka dots regularly dispersed on the technical backside of the fabric, the non-terry areas will be identical to the backside of a plain jersey fabric, i.e. dull, and completely devoid of surface interest.
Therefore, a primary objective of the current invention is to provide novel means whereby surface interest is developed at these normally plain areas. Accordingly, the patterned terry loop designs may be effectively enhanced and complemented by the development of surface interest effects in the adjacent non-terry loop portions of what normally constitutes the plain backside of the knitted fabric.
A further objective of the invention resides in the combination of patterned terry effects on the technical backside of the fabric and patterned ground stitch effects on the technical faceside and/or backside thereof by selective sinker actuation means synchronized to cooperate with selective needle actuation means.
The present invention further contemplates the addition of a third yarn into the terry fabric in a so-called non-knit manner so that the said third yarn when so incorporated occupies a position on the technical reverse side of the fabric, i.e. the same side on which the terry loops are made to appear. Inasmuch as this said third yarn component is not pulled through the loops of the previous course, but is introduced in a tuck or non-knit manner, it may be many times heavier than the ground and terry yarns and may in fact include novelty yarn such as boucle', seed, thick/thin, etc., in a broad range of constructions and sizes. Such a lay-in yarn need not have the strength requirements of the ground yarn. Furthermore, this lay-in effect yarn may be introduced on a regular overall basis on the technical backside, or, by appropriate needle selection means, may be caught into the fabric in a patterned lay-in configuration.
Inasmuch as both the terry loops and the lay-in effect appear on the technical backside of the fabric appropriate selection of terry loop-forming sinker elements in synchronized cooperation with appropriate selection of needles make possible the development of patterned areas of terry loops complemented by patterned areas developed with the effect or lay-in yarn.
When so introduced, the effect or novelty-type lay-in yarn effectively provides functional advantages, as well as aesthetics, to the knitted terry construction. Functionally, the effect yarn, by virtue of its introduction by non-knit or lay-in techniques, imparts, when required, improved widthwise stability to the knitted construction. Further, the heavy effect or lay-in yarn may be introduced at intermediate auxiliary feed positions between the terry loops of successive courses, thus helping the said terry loops in each as well as successive courses to be maintained more upstanding and, therefore, more respective to a subsequent shearing operation.
A major shortcoming of terry fabrics currently offered in the market which are to be sheared for a velour effect is that certain of the terry loops in the fabric have a tendency to lay somewhat inclined, well below the surface of other more upstanding terry loops. Consequently, when a fabric with this deficiency is to be sheared, the lower-lying loops remain untouched in the shearing process. Or, in order to insure that all terry loops are cropped, the shearing blade must be set sufficiently low to cut the lowermost terry loops. Understandably, this results in a lower overall sheared effect with resultant yarn waste. The introduction of a heavy lay-in yarn between the terry loops as provided in the current invention will help maintain terry loops of each and successive courses more erect and, therefore, easier to shear with a minimum of yarn wastage.
With regard to aesthetics, the incorporation of novelty yarns on the technical backside of a fabric in combination with terry loops on an overall or patterned basis may be effectively utilized in providing an added design element to enhance surface interest. If for example, the overall or patterned terry loop fabric incorporates a heavy boucle' novelty yarn introduced on a tuck or non-knit basis in one or more courses, and the terry loops subsequently sheared to a level, slightly above the level of the novelty yarn, then unusual fabric effects may be readily achieved in a broad range of sheared loop and novelty yarn combinations. Fabrics of this construction suggest excellent applications in apparel and upholstery.
Furthermore, for example, the terry loop portions on the backside of the fabric may appear as isolated upstanding polka dot motifs, and the remaining complementary potions, as flat patterned three-position effects in the ground fabric. In this instance, the terry loops yarn and the ground or body yarn constitute just the two yarns utilized throughout the knitted construction.
The invention further contemplates methods for producing patterned terry loop motifs in fabrics in combination with non-knit stitch effects, such that only terry loop yarn and ground yarn are used throughout the knitted construction. In the patterned terry portions developed at a specific feed, the terry yarn may be introduced over the nibs of selected sinkers and the ground yarn, into the sinker throats of all sinkers in the conventional way. At the same feed, when unselected sinkers remain outwardly inactive, ground stitches of plain jersey construction are formed with both the ground and so-called terry loop yarns again in a conventional manner. At a successive feed, however, at those portions where sinker elements are maintained outwardly inactive, needles may be selectively positioned to tuck and welt heights. Consequently, both the so-called terry yarn and ground yarn at said successive feed are caught simultaneously into the fabric in a non-knit or lay-in manner at those locations where terry loops are not formed. Consequently, by appropriate selection means, a broad range of unique patterned terry effects may be effectively combined with lay-in effects comprising the same terry and ground yarns only.
Likewise, sinker selection means may be synchronized with needle selection means, whereby knitting needle elements may be selectively positioned to knit, tuck, and welt levels. In these instances, the so-called terry loop yarn and the ground yarn are utilized alone throughout the fabric as noted above, combining to form areas of terry loops and complementary non-terry areas characterized by flat stitch knit, tuck, and welt combinations.
As previously described, where terry loops are to appear in a patterned configuration, the ground yarn is introduced into the throats of all sinkers and the terry yarn introduced above the nibs of selected sinkers. When the needles are subsequently retraced by conventional cam means, patterned terry effects are produced at those locations on the backside of the fabric where such sinker selection has been effected.
However, by synchronizing the needle selection to knit, tuck or welt levels at those locations in the fabric where terry loops are not formed, i.e., where sinkers are maintained in non-selected positions, then the so-called terry yarn and the ground yarn may be interknitted together in the base ground fabric in a plated relationship to provide patterned ground areas of non-terry loop construction to complement the patterned terry areas. The said patterned ground areas may be made to appear on the technical backside and/or faceside of the fabric. Consequently, by appropriate and complementary selection of both sinker elements and needle elements, whose actuations are synchronized with respect to each other, distinct and complementary pattern areas of terry loop and ground structure may be readily achieved in a broad range of novelty effects.
The invention resides further in a fabric produced on a machine of sinker-top construction with appropriate sinker selection and needle selection synchronized with respect to each other whereby terry loops are selectively formed at certain backside positions of the fabric as previously described. At other backside portions where terry loops do not appear, needles are selectively raised to a knit level higher than the normal knit position so that the so-called terry yarn is introduced on top of the latches of the selected needles, and the ground yarn, below the latches of selected needles. Inasmuch as certain needles are raised selectively to a high knit level, the ground yarn now occupies a position below the latches of these selected needles whereas the loop yarn will be on the latches of all needles. Consequently, when the needles are subsequently retracted by conventional cam means, while the terry yarn will be caught in the needle hooks and pulled down into loops, the ground yarn below the latches of selected needles, will pass up over the cheeks of these selected needles together with the previously formed loops thereby closing their latches and passing over the hooks of these needles into the fabric web. A lace-like open structure is thus made to appear at those places where needles have been selected to a high knit level. At those places where needles are raised to a conventional knit level, of course, the terry and ground yarns are both introduced above the needle latches and subsequently interknitted forming a standard jersey stitch comprising the two yarns in the basic fabric.
With this method, patterned terry loops effects on the technical backside may be effectively combined with other areas of lace-like open structure and plain jersey construction.
In addition, sinker selection as previously described for producing terry loops at specific portions on the technical backside of the fabric may be synchronized with appropriate selection of needles with forward hook construction whereby the so-called terry yarn is fed into the hooks of only the selected forward hook needles. When the forward hook unselected needles are subsequently advanced by conventional raising cam means to receive the ground yarn, the terry loop yarn is positioned behind these advancing needles. The terry yarn so introduced will be subsequently cast off over the hooks of the selected needles, thus creating lace-like open structures in the fabric web. Said lace-like open structures may be made to appear at the non-terry loop areas on the technical backside of the fabric. By virtue of the porous, lace-like fabric structure, a comfort factor is also achieved thus enhancing functional as well as aesthetic features of the knitted construction.